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Re: Function composition and currying
by oleg＠pobox.com 18 Jul '03

18 Jul '03

What I nice application for a multi-variadic compositional operator mcomp [1]. Only one operator does the trick, for functions of arbitrary number of curried arguments. And I really mean the arbitrary number of arguments, in both functions under composition. Given > f1 x = x*x > g2 a b = a + b > g3 a b c = a + b + c we can easily compose g2 with f1 *Main> (g2 `mcomp` f1) (1::Int) (2::Int) 9 and g3 with f1 *Main> (g3 `mcomp` f1) (1::Int) (2::Int) (3::Int) 36 But we can just as easily compose f1 with g2: *Main> (f1 `mcomp` g2) (2::Int) (3::Int) 7 (that is, square the first number and add the second) and f1 with g3 *Main> (f1 `mcomp` g3) (2::Int) (3::Int) (4::Int) 11 What's more, we can even compose g2 with g3 or g3 with g2! *Main> (g3 `mcomp` g2) (1::Int) (2::Int) (3::Int) (4::Int) 10 *Main> (g2 `mcomp` g3) (1::Int) (2::Int) (3::Int) (4::Int) 10 The Web page referenced below shows an advanced application of mcomp, to point-free programming (categorical products). [1] http://pobox.com/~oleg/ftp/Haskell/types.html The following code, excerpted from [1], was used for the above examples. -fglasgow-exts are needed. > class MCompose f2 cp gresult result | f2 cp gresult -> result, f2->cp > where > mcomp:: (f1->f2) -> (cp->gresult) -> (f1 -> result) > > -- Class instances. Please keep in mind that cp must be a non-functional type > -- and f2 and cp must be the same. These instances enumerate the base cases. > > instance MCompose (Maybe b) (Maybe b) c c where > --mcomp f::(a->(Maybe b)) g::((Maybe b)->c) :: a->c > mcomp f g = g . f > > instance MCompose [b] [b] c c where > --mcomp f::(a->[b]) g::([b]->c) :: a->c > mcomp f g = g . f > > instance MCompose Int Int c c where > --mcomp f::(a->Int) g::(Int->c) :: a->c > mcomp f g = g . f > > instance MCompose Char Char c c where > --mcomp f::(a->Char) g::(Char->c) :: a->c > mcomp f g = g . f > > instance MCompose (a,b) (a,b) c c where > mcomp f g = g . f > > -- Induction case > instance (MCompose f2 cp gresult result) => > MCompose (f1->f2) cp gresult (f1->result) where > mcomp f g = \a -> mcomp (f a) g >

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Announce: Haskell All-In-One
by Hal Daume III 17 Jul '03

17 Jul '03

Hi All, There have been several requests for such a program in the past, so I figured I'd finally break down and write it. Haskell All-In-One is a Haskell utility which will take a program implemented in multiple modules and convert it to a single module. It implements all of Haskell 98 (sorry, your -fglasgow-exts programs won't parse with the Language.Haskell.Parser parser so we can't deal with them, yet) as well as the hierarchical libraries. It can also correctly deal with literate Haskell scripts (provided you have GHCs unlit software available) and programs which need to be run through the c-pre-processor. The program, together with a bunch of documentation, is available at: http://www.isi.edu/~hdaume/HAllInOne/ There is one known bug (listed on the web page), but there are likely other unknown bugs. I would have liked to have run it on itself as a proof of concept, but unfortunatly it uses the GMap library, which require extensions and thus it cannot parse correctly. However, it's been tested against the GHC module regression suite and performs (almost) perfectly. I would appreciate bug reports, if you find any problems. On the TODO list currently are: - simplify and comment the source better - fix the known bug It requires GHC6.0 to compile "out of the box" with -fglasgow-exts and -fallow-undecidable-instances. It can compile with GHC 5.04.3, but will also need "-package haskell-src" and you will need to modify the code such that System.IO no longer imports 'bracket' and uncomment the 'cast' function in the GMap library. - Hal -- Hal Daume III | hdaume(a)isi.edu "Arrest this man, he talks in maths." | www.isi.edu/~hdaume

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COORDINATION 2004 - First Call for papers
by Emilio Tuosto 17 Jul '03

17 Jul '03

Please apologize if you receive multiple copies of this message. COORDINATION 2004 Preliminary Call for Papers Sixth International Conference on Coordination Models and Languages 24-27 February 2004 Pisa, Italy http://www.di.unipi.it/Coordination2004 (under construction) =============================================== IMPORTANT DATES: Submission of abstract: September 22, 2003 Submission of Papers: September 29, 2003, Notification of Acceptance: November 14, 2003 Camera-Ready Copy: December 4, 2003 CONFERENCE OBJECTIVES The need for increasing programming productivity and rapid development of complex systems provide the pragmatic motivation for the development of coordination/orchestration languages and models. The intellectual excitement associated with such endeavors is rooted in the decades-old desire to leverage off increasingly higher levels of abstractions. Coordination-based methods provide a clean separation between individual software components and their interactions within their overall software organization. Coordination is relevant in design, development, debugging, maintenance, and reuse of all complex concurrent and distributed systems. Specifically, coordination becomes paramount in the context of open systems, systems with mobile entities, and dynamically re-configurable evolving systems. Moreover, coordination models and languages focus on such key issues in Component Based Software Engineering as specification, interaction, and dynamic compositions. More recently, market trends brought on by the commercialization of the World Wide Web, have fuelled a new level of interest in coordination-based approaches in industry. Applications like BizTalk, standards like the web services' WS-* family, and contending coordination standards like BEPL4WS and WSCI, are all examples of this phenomenon. This interest is opening up new opportunities both to apply coordination-based techniques to a broad class of applications as well as to grapple with potentially new kinds of requirements coming from internet-scale scenarios. PREVIOUS EDITIONS The previous conferences in this series took place in Cesena (Italy), Berlin (Germany), Amsterdam (Netherlands), and Limasol (Cyprus), York (England). Building on the success of these events, this conference provides a forum for the growing community of researchers interested in models, languages, and implementation techniques for coordination and component-based software, as well as applications that utilize them. At http://music.dsi.unifi.it/coordination/ more details are available. TOPICS OF INTEREST (include, but are not limited to): * Theoretical models and foundations for coordination * Coordination middlewares * Specification, refinement, and analysis of software architectures * Architectural, and interface definition languages * Agent-oriented languages and models * Dynamic software architectures * Component Programming * Web Services * Coordination in Peer to Peer and Grid Computing * Tools and environments for the development of coordinated applications * Industrial relevance of coordination and software architectures * Domain-specific software coordination models and case studies. PROCEEDINGS The conference proceedings will be published by Springer, in the Lecture Notes in Computer Science series. The proceedings of the previous editions are appeared in the LNCS series: volumes 1061, 1282 and 1594, 1906, 2315. SUBMISSIONS Electronic submission will be used using conference web site: http://www.di.unipi.it/Coordination2004 (see also http://music.dsi.unifi.it/coordination) Authors are invited to submit electronically a plain ASCII cover page containing the paper title, authors' names, contact author and full address (including e-mail and fax) together with an abstract of up to 100 words (no later than 22 September 2003). Full papers (in English, up to 6000 words) should be submitted in PostScript or PDF no later than 29 September 2003. Authors are invited to use the llncs style. A link will be found the conference web page. Simultaneous submission to other conferences with proceedings or journals is not allowed. LOCATION The conference will be held in Pisa, Dipartimento di Informatica, Via F.Buonarroti 2. Program co-chairs Rocco De Nicola (Univ. Firenze) Greg Meredith (Microsoft) Organizing Chair Gianluigi Ferrari (Univ. Pisa) Program Committee: Roberto Amadio, Univ. Marseilles - France Farhad Arbab, CWI - The Netherlands Marcelo Bonsangue, Leiden University - The Netherlands Paolo Ciancarini, Univ. Bologna Italy José Fiadeiro, Univ. Leicester - United Kingdom Chris Hankin, Imperial Colege - United Kingdom Jean-Marie Jacquet, Univ. Namur - Belgium Antonia Lopes, Univ. of Lisbon - Portugual Jeff Magee Imperial College - United Kingdom George Papadopoulos, Univ. Cyprus - Cyprus Gian Pietro Picco, Politecnico di Milano -Italy Rosario Pugliese, Univ. Firenze - Italy Gruia-Catalin Roman, Washington University in St. Louis,USA Ant Rowstrom, Microsoft Cambridge - United Kingdom Vijay Saraswat, PennState Univ. - USA Carolin Talcott SRI - USA Robert Tolksdorf, Free University of Berlin Germany Herbert Wiklicky, Imperial College - United Kingdom Alan Wood, Univ. York - United Kingdom Franco Zambonelli, Univ. Modena - Italy Organizing Committee Andrea Bracciali, Univ. Pisa, Italy, Robero Bruni, Univ. Pisa, Italy, Antonio Cisternino, Univ. Pisa, Italy, Dan Hirsch, Univ. Pisa, Italy, Laura Semini, Univ. Pisa, Italy, Emilio Tuosto, Univ. Pisa, Italy, Further Information - COORDINATION2004 Web site: http://www.di.unipi.it/Coordination2004 - For questions: coordination2004(a)di.unipi.it --

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ICFP 2003 -- Call for Participation
by Olin Shivers 17 Jul '03

17 Jul '03

ICFP (the International Conference on Functional Programming) is coming up soon -- August 25-29, in Uppsala, Sweden. The following "Call for Participation" has the important bits, but here are the two key things you need to know if you are thinking of attending this year: - Registration is open *now*. - You want to register *well before* July 30 -- the deadline for early registration is 7/30, and most hotels will close out their guaranteed reservations by then, if not earlier. I also append the complete program of talks. See you in Sweden... -Olin Shivers program chairman ------------------------------------------------------------------------------- Call for Participation ICFP 2003: ACM International Conference on Functional Programming August 25-29, 2003 Uppsala, Sweden * About ICFP ------------ The goal of ICFP is to - stimulate and promote international research on functional programming, and - act as focal point to bring together the functional-programming community for intellectual cross-pollination and collaboration. The scope of the conference includes all languages that encourage programming with functions, including both purely applicative and imperative languages, as well as languages that support objects and concurrency. The topics covered range from principles to practice, from foundations to features, and from abstractions to applications. The conference is affiliated with PLI, a confederation of international meetings sponsored by ACM SIGPLAN, which this year will also include - PPDP (International Conference on Principles and Practice of Declarative Programming) - LOPSTR (International Symposium on Logic-based Program Synthesis and Transformation) - Haskell Workshop - Erlang Workshop - MERLIN (Mechanised Reasoning About Languages with Variable Binding) - DPCOOL (Declarative Programming in the Context of Object-oriented Languages) * Useful URLs ------------- - Main web page for the entire PLI meeting; contains information on accepted papers, registration, accomodation, and social events: http://www.it.uu.se/pli03/ - Main web page for ICFP: http://www-users.cs.york.ac.uk/~colin/icfp2003.html - ICFP programme: http://www.cc.gatech.edu/~shivers/icfp03/schedule.html * Registration now open ----------------------- Registration is now open and the early registration deadline is July 30th. NOTE: The cut-off date for guaranteed hotel reservations varies with the hotel and is typically *before* July 30th. It is advisable to make your hotel reservations soon. ------------------------------------------------------------------------------- * Conference programme ---------------------- Monday 25 August 2003 Invited talk: 9:00-10:00 ------------------------ Conservation of information: Applications in functional, reversible, and quantum computing Thomas Knight, Jr. (MIT Artificial Intelligence Laboratory) Session I: 10:30-12:30 ---------------------- Scripting the type-inference process Bastiaan Heeren, Jurriaan Hage, Doaitse Swierstra (Universiteit Utrecht) Discriminative sum types locate the source of type errors Matthias Neubauer, Peter Thiemann (Universität Freiburg) MLF: Raising ML to the power of system F Didier Le Botlan, Didier Remy (INRIA Rocquencourt) An extension of HM(X) with bounded existential and universal data-types Vincent Simonet (INRIA Rocquencourt) Session II: 2:15-3:45 --------------------- CDuce: an XML-centric general-purpose language Véronique Benzaken (LRI, Université Paris Sud, Orsay), Giuseppe Castagna (CNRS, LIENS, École Normale Supérieure), Alain Frisch (LIENS, École Normale Supérieure, Paris) Compiling regular patterns Michael Levin (University of Pennsylvania) Software is discrete mathematics Rex Page (University of Oklahoma) Session III: 4:15-6:00 ---------------------- Global abstraction-safe marshalling with hash types James Leifer (INRIA Rocquencourt), Gilles Peskine(INRIA Rocquencourt), Peter Sewell (University of Cambridge), Keith Wansbrough (University of Cambridge) Dynamic rebinding for marshalling and update, with destruct-time lambda Gavin Bierman (University of Cambridge), Michael Hicks (University of Maryland, College Park), Peter Sewell (University of Cambridge), Gareth Stoyle (University of Cambridge), Keith Wansbrough (University of Cambridge) Iterative-free program analysis Mizuhito Ogawa (Japan Advanced Institute of Science and Technology), Zhenjiang Hu (University of Tokyo), Isao Sasano (Japan Advanced Institute of Technology and Science) Report on ICFP 2003 & 2004 Olin Shivers & Kathleen Fisher =============================================================================== Tuesday 26 August 2003 Invited talk: 9:00-10:00 ------------------------ From Hilbert space to Dilbert space: Context semantics as a language for games and flow analysis Harry Mairson (Brandeis University) Session IV: 10:30-12:30 ----------------------- A theory of aspects David Walker (Princeton University), Steve Zdancewic (University of Pennsylvania), Jay Ligatti (Princeton University) Dependency-style Generic Haskell Andres Löh, Dave Clarke, Johan Jeuring (Universiteit Utrecht) Functional automatic differentiation with Dirac impulses Henrik Nilsson (Yale University) A user-centred approach to functions in Excel Simon Peyton Jones (Microsoft Research), Alan Blackwell (University of Cambridge), Margaret Burnett (Oregon State University) Session V: 2:15-3:45 -------------------- A sound and complete axiomatization of delimited continuations Yukiyoshi Kameyama (University of Tsukuba), Masahito Hasegawa (Kyoto University) Call-by-value is dual to call-by-name Philip Wadler (Avaya Labs) Disjunctive normal forms and local exceptions Emmanuel Beffara, Vincent Danos (Université Paris 7) Session VI: 4:15-6:00 --------------------- An effective theory of type refinements Yitzhak Mandelbaum (Princeton University), David Walker (Princeton University), Robert Harper (Carnegie Mellon University) A static type system for JVM access control Tomoyuki Higuchi, Atsushi Ohori (Japan Advanced Institute of Science and Technology) Parsing polish, step by step (functional pearl) John Hughes (Chalmers University), Doaitse Swierstra (Universiteit Utrecht) Programming contest awards presentation John Hughes et al. (Chalmers University of Technology) =============================================================================== Wednesday 27 August 2003 Session VII: 9:00-10:30 ----------------------- Boxes go bananas: Encoding higher-order abstract syntax with parametric polymorphism Geoffrey Washburn, Stephanie Weirich (University of Pennsylvania) FreshML: Programming with binders made simple Mark Shinwell, Andrew Pitts, Murdoch Gabbay (University of Cambridge) Meta-programming through typeful code representation Chiyan Chen, Hongwei Xi (Boston University) Session VIII: 11:00-11:30 ------------------------- Optimistic evaluation: An adaptive evaluation strategy for non-strict programs Robert Ennals (University of Cambridge), Simon Peyton Jones (Microsoft Research) Invited talk (joint with PPDP'03): 11:30-12:30 ---------------------------------------------- Understanding aspects Mitchell Wand (Northeastern University)

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FM 2003 Call for Participation
by mailinglist-admin＠fmeurope.org 16 Jul '03

16 Jul '03

Sorry if some of you receive multiple copies of this message. Stefania Gnesi (FM2003 General Chair) ============================================================================== Call for Participation ------------------------------------------------------------------------------ The 12th International FME Symposium Pisa, Italy - September 8-14, 2003 http://fme03.isti.cnr.it - fme03(a)isti.cnr.it ------------------------------------------------------------------------------ FM 2003 is the twelfth in a series of symposia organized by Formal Methods Europe, an independent association whose aim is to stimulate the use of, and research on, formal methods for software development. These symposia have been notably successful in bringing together a community of users, researchers, and developers of precise mathematical methods for software development as well as industrial users. Formal methods have been controversial throughout their history, and the realization of their full potential remains, in the eyes of many practitioners, merely a promise. Have they been successful in industry? If so, under which conditions? Has any progress been made in dispelling the skepticism that surrounds them? Are they worth the effort? Which aspects of formal methods have become so well established in the industrial practices to loose the "formal method" label in the meanwhile? FM 2003 aims to answer these questions, by contributions not only from the Formal Methods community but also from outsiders and even from skeptical people who are most welcome to explain, document, and motivate the source of their reluctance. Satellite Events FM 2003, will host 7 Workshops, 8 Tutorials and 1 Day dedicated to the Industry besides the 3 days of the FME Symposium. Tool demonstrations will also take place during the symposium, with the opportunity of holding presentations for each tool. For full details on the Symposium organization and to register please see the web site http://fme03.isti.cnr.it, or send your query to fme03(a)isti.cnr.it. _______________________________________________ Mailinglist mailing list Mailinglist(a)fmeurope.org http://www.fmeurope.org/mailman/listinfo/mailinglist

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Re: Unicode + Re: Reading/Writing Binary Data in Haskell
by George Russell 14 Jul '03

14 Jul '03

Glynn wrote (about my binary library, snipped): > This is similar to UTF-8; however, UTF-8 is a standard format which > can be read and written by a variety of other programs. > > If we want a mechanism for encoding arbitrary Haskell strings as octet > lists, and we have a free choice as to the encoding, UTF-8 is > definitely the way to go. No I don't think so. UTF8 is a good choice if you want a way of storing Unicode files on an 8-bit file-system, but it is not as efficient an encoding for characters in general. Thus with UTF8 you can represent character codes less than 2^11 in two bytes; with my system you can represent codes less than 2^14. In 3 bytes, UTF8 can represent codes less 2^16; I can do anything less than 2^21. This is not an error in UTF8's design; I think it's because UTF8 includes extra bits which make it much easier to use UTF8-encoded files with tools, such as "grep", which were only written with 8-bit characters in mind. That is not a design aim for us. Furthermore UTF8's encoding is in fact rather more complicated to program than mine, and the implementor will need an encoding like mine in any case to encode arbitrary-size integers (something UTF8 encoding can't do by the way). If we think for a moment what a Haskell system using UTF8 would be like, I think it's easiest to imagine that in future there will be a way of specifying that a file contains character data stored in UTF8 format, either as a flag stored in the filing system, or as an option given to functions like Haskell's openFile. Or perhaps openFile would assume UTF8, and there will be an openBinaryFile which does not. However it's done, this is entirely orthogonal to the question of how to encode character data as binary *within* Haskell. > However, that isn't the issue which was being discussed in this > thread. The issue is that we need a standard mechanism for reading and > writing *octets*, so that Haskell programs can communicate with the > rest of the world. Yes we do. At the moment my binary library does of course have to use standard character input, plus a couple of internal GHC functions (for writing blocks of data), and I hope that there will someday be standard functions I can use instead.

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IFL/TFP 2003 2nd call for participation/registration
by Greg Michaelson 14 Jul '03

14 Jul '03

Joint IFL/TFP 2003 2nd Call For Participation ****** REGISTRATION NOW OPEN ****** Between 8th and 12th September 2003 the - 15th Int. Workshop on the Implementation of Functional Languages http://www.macs.hw.ac.uk/~ifl03 - 4th Int. Symposium on Trends in Functional Programming http://homepages.inf.ed.ac.uk/stg/workshops/TFP/ will be co-located in Edinburgh Both calls for papers are appended below. ============================================================= IFL 2003 15th International Workshop on the IMPLEMENTATION OF FUNCTIONAL LANGUAGES Edinburgh Scotland September 8th - 10th, 2003 http://www.macs.hw.ac.uk/~ifl03 ============================================================= Important dates --------------- Registration deadline: August 1st, 2003 Submission deadline : August 22nd, 2003 Workshop : September 8-10th, 2003 ============================================================= Scope of IFL 2003 ----------------- The aim of the workshop is to bring together researchers and users actively engaged in the implementation and application of functional programming languages to discuss results and new directions of research. The workshop is intended to provide an open forum for researchers who wish to present and discuss new ideas and concepts, work in progress, preliminary results etc. related primarily but not exclusively to the implementation of functional or function-based languages. A not necessarily exhaustive list of topics includes language concepts type checking compilation techniques (abstract) interpretation automatic program generation (abstract) machine architectures array processing concurrent/parallel programming and program execution heap management runtime profiling and performance measurements debugging and tracing verification of functional programs tools and programming techniques Contributions on applications of functional programming, e.g., in teaching, or on theoretical work in any of the above areas are also welcome. This year's workshop is co-located with the 4th International Symposium on Trends in Functional Programming (TFP'03) <http://homepages.inf.ed.ac.uk/stg/workshops/ISTFP/>. Contributions ------------- All attendees are encouraged to submit papers to be published in the draft proceedings and to give presentations at the workshop. Submitted papers must be written in English, conform to the LNCS format (available at: http://www.springer.de/comp/authors/index.html) and not exceed 16 pages. Papers should be submitted by August 22nd as postscript or pdf files using the submission page of the workshop accessible through http://www.macs.hw.ac.uk/~ifl03 After the workshop, a high-quality subset of contributions will be published in the Springer LNCS series. All speakers attending the workshop are invited to submit a paper. Papers for the LNCS proceedings will be refereed according to normal conference standards. Greg Michaelson and Phil Trinder (Organizing Committee Chairs) School of Mathematical and Computer Sciences Heriot-Watt University Edinburgh, EH14 4AS E-mail: {greg,trinder}@macs.hw.ac.uk Teleph: +44 (0)131 451 3435 Depart: +44 (0)131 451 3328 Fasmly: +44 (0)131 451 3327 Intrnt: http://www.macs.hw.ac.uk/~greg http://www.macs.hw.ac.uk/~trinder ============================================================ TFP 2003 Fourth International symposium on Trends in Functional Programming Edinburgh, Scotland September 11th - 12th, 2003 http://homepages.inf.ed.ac.uk/stg/workshops/TFP/ The international symposium on Trends in Functional Programming continues the Scottish Functional Programming Workshop series. These workshops bring together researchers with interests in all aspects of functional programming languages. Papers on all aspects of functional programming are welcomed, be they implementation-oriented, theoretical, or experience papers. This year's workshop is co-located with the 15th International Workshop on the Implementation of Functional Languages (IFL '03) <http://www.macs.hw.ac.uk/~ifl03>. Workshop Topics Papers on any aspect of functional programming are welcome. Papers on the following subject areas are particularly welcome. * rich type systems, including type systems for expressing resource bounds or other safety properties; * linear type systems, soft type systems, typeful programming; * reasoning about functional programs, semantics of functional languages; * inductive or co-inductive techniques, proof nets; * mobile-code functional programming languages; * parallel programming with functional languages, cost models for functional programs; * compilation of functional languages for the Java Virtual Machine; * functional aspects of imperative programming, functional bytecode; * interoperability with imperative programming languages, calling imperative from functional or vice versa; * type inference algorithms, type error repair, deep types; * strongly-typed imperative languages with inference (e.g. Cyclone); * performance measurements, optimisation techniques, implementation techniques; * experience papers: applications of functional programming or functional programming in education. The above list is not exhaustive. Papers on other topics are also welcome. Contributions All attendees are encouraged to submit papers to be published in the draft proceedings and to give presentations at the workshop. Submitted papers must be written in English and not exceed 16 pages. Papers should be written conform to the LNCS format <http://www.springer.de/comp/lncs/authors.html> and should be submitted as postscript (or pdf) by email to the workshop chair, Stephen Gilmore <stg(a)inf.ed.ac.uk>. Proceedings We intend to publish a refereed, high-quality subset of contributions in the final proceedings. The proceedings publisher is to be confirmed: previous SFP proceedings were published by Intellect. All speakers attending the workshop are invited to submit a paper. Papers for the proceedings will be refereed according to normal conference standards. This implies (among other things) that: * the paper should be written in English * the paper is well written * topic of the paper should be stated clearly * the approach to solve the problem should be outlined clearly * a detailed discussion of the solution has to be given * the solution is compared with relevant related work * there is an abstract, introduction and conclusion. * the conclusion should summarise the problem, the solution, and how this solves the problem. * the paper should not exceed 16 pages. * the paper should be written to conform to the LNCS format <http://www.springer.de/comp/lncs/authors.html>. * the paper should be submitted as postscript (or pdf) by email to the workshop chair, Stephen Gilmore <stg(a)inf.ed.ac.uk>. Dates Aug 2nd 2003 : Submission for draft proceedings Sept 11th - Sept 12th 2003 : Workshop Oct 31st 2003 : Submission for referees process Dec 12th 2003 : Notification of acceptance/rejection Jan 23rd 2004 : Camera-ready papers Event Site The workshop will take place at The Pollock Halls in the city center of Edinburgh <http://www.accom.ed.ac.uk/maps/pollock.htm>. Previous workshops The TFP workshop continues the Scottish Functional Programming Workshop series. The previous SFPW meetings were Stirling (2001), St. Andrews (2000), Stirling (1999). Program Committee Sharon Curtis <http://wwwcms.brookes.ac.uk/~p0073860/> Oxford Brookes University Stephen Gilmore (Chair) <http://homepages.inf.ed.ac.uk/stg/> The University of Edinburgh Kevin Hammond <http://www.dcs.st-and.ac.uk/~kh/> University of St Andrews Hans-Wolfgang Loidl <http://www.tcs.informatik.uni-muenchen.de/~hwloidl/> Ludwig-Maximilians-Universitat, Munchen Bruce McAdam <http://www.scms.rgu.ac.uk/staff/bjm/> Robert Gordon University Greg Michaelson <http://www.cee.hw.ac.uk/~greg/> Heriot-Watt University John O'Donnell <http://www.dcs.gla.ac.uk/~jtod/> University of Glasgow Phil Trinder <http://www.cee.hw.ac.uk/~trinder/> Heriot-Watt University

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Unicode + Re: Reading/Writing Binary Data in Haskell
by George Russell 14 Jul '03

14 Jul '03

Martin quoted Glynn: > OTOH, existing implementations (at least GHC and Hugs) currently read > and write "8-bit binary", i.e. characters 0-255 get read and written > "as-is" and anything else breaks, and changing that would probably > break a fair amount of existing code. The binary library I posted to the libraries list: http://haskell.org/pipermail/libraries/2003-June/001227.html which is for GHC, does this properly. All characters are encoded using a standard encoding for unsigned integers, which uses the bottom 7 bits of each character as data, and the top bit to signal that the encoding is not yet complete. Characters 0-127 (which include the standard ASCII ones) get encoded as themselves. This is probably not nearly as efficient as encoding characters as themselves, but it's nice to be Unicode-proof ...

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Reading/Writing Binary Data in Haskell
by Gordon James Miller 13 Jul '03

13 Jul '03

Hello to all, I'm recently working on doing some atmospheric modelling for my PhD thesis work and I've been writing parallel implementations in Java, Ruby, and Haskell. I picked up Haskell as part of the LoTY project and was especially impressed by how expressive and clean the code is. I've been quite successful at writing most of my numerical libraries in Haskell (typically at a much reduced SLOC) but I'm not butting my head against binary data. I have a large store of data, output by a Fortran model, which essentially consists of binary files containing arrays of floating point values. In doing some googling on reading binary data in Haskell I've come across some old (> 1 year) references to some mailing list discussions on reading binary data. So given the background I have a few questions: 1 - Is there yet a standard, or at least commonly supported by hugs and ghc, method for dealing with binary data. 2 - If not, is there a "standard" library that is used to manipulate binary data. I've seen some references to some implementations but given that this is being done in my limited spare time (I'm not a full time student) I'd rather not spin my wheels on something that's going to be dead in a matter of months. 3 - What is the current status of getting binary data into the Haskell standard? I understand that I can write a C extension, but part of my interest in Haskell lies in the ability to write scientific software that very closely resembles the mathematics that are being modelled. On that note, I'd also be very interested in conversing with people that are doing physics modelling (atmospheric dynamics and chemistry is esp. interesting) using functional languages. Thanks! Gordon Miller gmiller(a)bittwiddlers.com

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Re: How overload operator in Haskell?
by Liu Junfeng 12 Jul '03

12 Jul '03

I come up a solution as this: --------------------------------------------------- module Vector where data Vector =Vector [Double] fromVector :: Vector -> [Double] fromVector (Vector v) = v fromList :: [Double] -> Vector fromList v = Vector v toVector :: Double -> Vector toVector x = Vector (repeat x) instance Eq Vector where v1 ==v2 = (fromVector v1) == (fromVector v2) instance Show Vector where show v = show (fromVector v) instance Num Vector where v1 + v2 =Vector (zipWith (+) (fromVector v1) (fromVector v2)) v1 - v2 =Vector (zipWith (-) (fromVector v1) (fromVector v2)) v1 * v2 =Vector (zipWith (*) (fromVector v1) (fromVector v2)) signum v = Vector (map signum (fromVector v)) abs v = Vector ((repeat.sqrt.sum.fromVector) (v*v)) fromInteger n =Vector (repeat (fromInteger n)) instance Fractional Vector where v1 / v2 = Vector (zipWith (/) (fromVector v1) (fromVector v2)) fromRational r =Vector (repeat (fromRational r)) -------------------------------------------------------------------------- rk4 :: ((Vector,Vector)->Vector)->Vector->Vector->Vector->[Vector] rk4 _ _ _ (Vector []) = [] rk4 f h y0 (Vector (x0:xs)) = y0 :rk4 f h y1 (Vector xs) where y1=yp f h (toVector x0) y0 yp ::((Vector,Vector)->Vector)->Vector->Vector->Vector->Vector yp f h x y = y + (k1 + 2 * (k2 + k3) + k4) where k1=h*f(x,y) k2=h*f(x+0.5*h, y +(0.5*k1)) k3=h*f(x+0.5*h, y +(0.5*k2)) k4=h*f(x+h, y+k3) a=let g (x,y1) = y1 x0 = 0 h = 0.01 x =Vector [x0,x0+h..3] y0 =Vector [0,0.5] in rk4 g (toVector h) y0 x -------------------------------------------------------------------------- The main problem is how to make type convert implicitly. Whem a function needs a vector as its parameter, pass a double and it is converted to vector implicitly. ======= 2003-07-12 12:18:00 Jon Fairbairn Wrote��======= >On 2003-07-12 at 20:20+1000 Andrew J Bromage wrote: >> G'day all. >> >> On Fri, Jul 11, 2003 at 04:28:19PM -0400, Dylan Thurston wrote: >> >> > Don't be silly [...] >> >> Never! > >Or only sometimes. I'm surprised that no-one has yet >answered the question "How overload operator in Haskell?" >with "Overload operator in Haskell fine". (cf Cary Grant) I am also surprised at this, it can be done by C++ . > >-- >J�n Fairbairn Jon.Fairbairn(a)cl.cam.ac.uk >31 Chalmers Road jf(a)cl.cam.ac.uk >Cambridge CB1 3SZ +44 1223 570179 (after 14:00 only, please!) > > >_______________________________________________ >Haskell mailing list >Haskell(a)haskell.org >http://www.haskell.org/mailman/listinfo/haskell = = = = = = = = = = = = = = = = = = = = Regards, Liu Junfeng liujf(a)softhome.net 2003-07-12

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